Light

Last Saturday, my wife and I watched Angels and Demons. Overall, the movie was entertaining. The scenery in Rome brought us happy memories of our previous trip.

Compared to The Da Vinci Code, the clues and mysteries in this work were a bit thin. Robert Langdon must be very lucky to get the secret path right.

In this story, terrorists disguised as members of the secret organization of Illuminati stole a canister containing some antimatter, which was supposed to be a dangerous substance that could produce huge explosion. To create fear, the terrorists hid the canister somewhere in Vatican City and transmitted its image to the police. The job of Robert Langdon and the police was to find the canister as well as the people behind the plot.

They soon thought of a good idea. By turning off lights at different parts of Vatican City one at a time, they could roughly locate the canister when the TV image became dark. The trouble was there were too many areas in the City and they only had four hours. The canister would probably explode before they could locate it. Nevertheless, the police decided to proceed, slowly but surely.

At this point, I could not help thinking, “Hey, this is a simple IQ test. Four hours is more than enough.”

Do you know how?

The correct approach is to turn off half of the lights in the whole City. If the canister is in the dark side, you have already excluded half of the City. Then you turn off half of the lights in the remaining part, so on and so forth. Repeating the exercise ten times is equivalent to testing 2 to the power 10, or 1024 spots. Repeating the exercise twenty times is equivalent to testing 1,048,576 spots. They should even have time to send the canister back to the physics lab.

This is the power of amplification. Solving a simple problem in a movie is of course nothing. Honor should go to Kary Mullis, who invented the polymerase chain reaction just by thinking about these numbers.